The invention relates generally to a membrane structure. More particularly, the invention relates to a membrane structure having substantially high flux and substantially high selectivity. The invention also relates to a method of making a membrane structure.
Porous membrane structures have been extensively used in filtration, separation, catalysis, detection, and sensor applications. Realizing membrane structures with fine pores and high flux is difficult, as the flux through the membrane decreases with decreasing pore size. Therefore, typically layers with fine pores are made very thin. Fabricating thin porous layers with uniform pores over large surface area and which are mechanically robust is a challenging task. Therefore, typically thin fine porous membranes are stacked on thicker substrates with coarser pores. In such membrane structures it is extremely difficult to get a defect free smooth interface between layers to ensure faultless connectivity through the membrane structure. In spite of much effort, the currently available membrane structures with fine pores exhibit undesirably low permeance. Therefore, it is desirable to improve the efficiency of fine porous membrane structures suitable for high temperature, high pressure, and/or corrosive atmospheres.